Field of the Invention
The present invention relates to an image capturing apparatus, and a control method therefor.
Description of the Related Art
In recent years, there are increasing needs for the users of digital cameras to know the image capturing position and image capturing direction of photographs. And, a digital camera including an electronic compass that uses a geomagnetic sensor and an acceleration sensor, and having a function of saving the image capturing direction in association with a captured image, has come into practical use. For example, Japanese Patent Laid-Open No. 2000-32379 discloses a technique in which image information is associated with image capturing orientation information and image capturing field angle information, and a composite image having a wide field angle is generated from a plurality of images based on the associated information.
The electronic compass calculates orientation based on the outputs of the geomagnetic sensor and the acceleration sensor. Accordingly, if there is an obstacle that affects the magnetic field and the acceleration within the digital camera or in the digital camera system, in principle, the accuracy of the calculated orientation is reduced. Japanese Patent Laid-Open No. 2013-57601 proposes a method for avoiding this problem that arises in the geomagnetic sensor. Japanese Patent Laid-Open No. 2013-57601 discloses an electronic device including a geomagnetic detection unit, a change amount calculation unit that calculates the amount of change in magnetic orientation data, and an integration unit that integrates angular velocity so as to calculate angle data. With this electronic device, if the amount of change in magnetic orientation data and the angular velocity are within a threshold value range, the orientation is calculated using the geomagnetism. Otherwise, the orientation is calculated using the angular velocity in addition to the geomagnetism.
A digital camera, in particular, a single-lens reflex digital camera includes movable units such as a mirror and a shutter, and as a result of these units being moved at the time of image capturing, the acceleration sensor is affected, and the accuracy of the calculated orientation is reduced. However, Japanese Patent Laid-Open No. 2013-57601 merely discloses measures to reduce the influence on the geomagnetism, and does not disclose measures to reduce the influence on the acceleration.